Rheostat



A. HALL May 6, 1930.

RHEOSTAT Filed July 5. 1929 JnUQTUE-I": vqrthur Hall 5.9 Jilly PatentedMay 6, 1930 UNITED STATES PATENT OFFICE ARTHUR HALL, on OAK PARK,ILLLINOISMASSIGNOR 'ro YAxLEY MANUFACTURING COMPANY, or CHICAGO,ILLINOIS, A CORPORATION or ILLINOIS RHEOSTA'I Application filed July 5,

the circular walls of containing cups and has I for its object theprovision of an improved assemblage of the bearing for the shaft of sucha .rheostat with the end wall of such a containing cup. In practicing myinvention inwardly extending prong or prongs are stamped from the endwall of such a cup. These prongs are equidistant from the center of thecup. They are clinched into holding engagement with a flange which isprovided upon one end of a bearing sleeve for the shaft of the rheostat,this sleeve end being 1 bottomed upon said cup end wall. This flange isdesirably polygonal so as to prevent the bearing sleeve from beingturned upon its axis, whileat the same time maintaining the bearingsleeve perpendicular to the cup end wall. a

I will explain my invention more fully by reference to the accompanyingdrawing in which Fig. 1 is a front view of the rheostat constructed inaccordance with the preferred form of the invention; Fig. 2 is asectional view on line 2-2 of Fig. 1; and Fig. 3'is a sectional view online 33 of Fig. 2.

The rheostat illustrated is inclusive of a resistance unit that employsa ribbon or strip of insulation 1 about which is wound the resistance 2of wire, such ribbon thus constituting the core of the resistance.Terminals 3 and 4 are mechanically assembled with the resistance coreandare electrically connected, respectively, with the ends of theresistance winding. A liner 5, also in the form of a strip or ribbon ofinsulation, encloses the resistance unit. This liner is also in the formof a split ring to permit of its expansion. The parts 1, 2. and 5 aredisposed within a metallic cup, these parts being surrounded bythewcircular cup wall 6. The'em'ployment of metal in the formation ofthe cup makes the employment of the liner 5 desirable. Where the linerand a cup of metal are employed, the liner is desirably continued alongthe bottom of the cup so as there also to insulate the resistance wirefrom the cup, Fig. 2.

The ends of the ring 1 are desirably spaced apart in the circle of thering. A spreading 1929. Serial No. 376,106.

device 7 operates upon-the ends of the core to expand this corecircumferentially, that is, n a generally circular direction, as setforth In my copending application Serial 7 No. 376,105 filed July 5,1929.

The cup is provided with a hub portion 8 that is coaxial therewith. Thishub portion constitutes a bearing for the shaft 9-upon which therheostat arm 10 is mounted, this rheosta't arm riding upon and havingelectrical contact with the adjacent edge of the hearing against theinner face of the end wall of the cup. Said bearing sleeve is providedwith a reduced threaded extension 8' which passes through a central holein theend wall of the cup. 11 clamping nut'12 is screwed upon the part 8and against the outer face of the end wall. of the cup, this end wallbeing thus clamped between the are firmly clinched over the flange 11 tohold the sleeve from turning. Further to ard against .the turning of thesleeve, the fl nge is desirably hexagonal or of other poly onal contour,the flat sides of the flange eing snugly engaged by the portions 13 thathave correspondingly flat flange engaging surfaces. The bearing sleeveis thus not only held from rotation but is held with the axisperpendicular to the end wall of the cup. A

split spring collar 9' holds the shaft 9 from axial movement. 4

Having thus described my invention, I claim;

1. A rheostat structure including a resistance unit; a cup surroundingthe resistance unit; a bearing sleeve disposed at the central portion ofthe cup perpendicularly to the. cup end wall and alsocontained in thecup; a shaft journaled in said sleeve; and a contact arm'upon the shaftand electrically ena gageable with the resistance unit, the end wall ofsaid cup having an inwardly projecting prong which is clinched intoengagement with said sleeve.

2. The structure of claim 1 wherein the 5 bearing sleeve is formed witha flange por- 7 tion into engagement with which the prong is clinched.

3. A rheostat structure including a resistance unit; a cup surroundingthe resistance 10 unit; a bearing sleeve disposed at the central port1onof the cup perpendicularly to the cup end wall and also contained in thecup;

a shaft journaled in said sleeve; and a. contact arm upon the shaft andelectrically eng ga cable with the resistance unit, the end wa 1 of saidcup having a plurality of prongs inwardly struck therefrom andequidistant from the center of the cup, said bearing sleeve having apoly onal flange whose sides are v closely engaged by said prongs.

In witness whereof, I hereunto subscribe my name.

ARTHUR HALL.

